We fabricated flat and homogeneous Al₂O₃/ZnO/Al₂O₃ heterostructure luminescent layers by atomic layer deposition (ALD) to serve as a nanometer-scaled light source for high-spatial-resolution optical microscopy based on electron beam excitation (EXA). A smooth surface was obtained by inserting an Al₂O₃ buffer layer and an Al₂O₃ barrier layer resulting in brighter and more uniform cathodoluminescence (CL) compared with that from a directly deposited ZnO layer. The root mean square (rms) value determined by atomic force microscope drastically decreased from 2.4nm (for typical ZnO film) to 0.5nm (for the six-layer pairs of the Al₂O₃/ZnO/Al₂O₃ heterostructure). The CL brightness increased by two times of that in the Al₂O₃/ZnO/Al₂O₃ heterostructure due to a waveguide effect. However, the increase in the number of the layer pairs from one to six reduced the CL brightness by half. The CL emission variability was about 30% improved that is supposed to enable high-resolution using Al₂O₃/ZnO/Al₂O₃ luminescent layers for an EXA microscope.

我们通过原子层沉积 (ALD)制造了平坦且均匀的 Al ₂ O ₃ /ZnO/Al ₂ O ₃异质结构发光层，用作基于电子束激发 (EXA) 的高空间分辨率光学显微镜的纳米级光源）。与直接沉积的 ZnO 层相比，通过插入 Al ₂ O ₃缓冲层和 Al ₂ O ₃阻挡层获得了光滑的表面，导致更亮和更均匀的阴极发光 (CL)。原子力显微镜测定的均方根 (rms) 值从 2.4nm（对于典型的 ZnO 膜）急剧下降到 0.5nm（对于 Al 的六层对）₂ O ₃ /ZnO/Al ₂ O ₃异质结构）。由于波导效应，CL亮度增加了Al ₂ O ₃ /ZnO/Al ₂ O ₃异质结构的两倍。然而，层对数量从 1 增加到 6 会使 CL 亮度降低一半。CL 发射变异性提高了大约 30%，这应该能够使用用于 EXA 显微镜的Al ₂ O ₃ /ZnO/Al ₂ O ₃发光层实现高分辨率。